#pragma ident "$Id$"

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//
//  This file is part of GPSTk, the GPS Toolkit.
//
//  The GPSTk is free software; you can redistribute it and/or modify
//  it under the terms of the GNU Lesser General Public License as published
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//  GNU Lesser General Public License for more details.
//
//  You should have received a copy of the GNU Lesser General Public
//  License along with GPSTk; if not, write to the Free Software Foundation,
//  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110, USA
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//  Copyright 2004, The University of Texas at Austin
//
//============================================================================

//============================================================================
//
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//Texas at Austin, under contract to an agency or agencies within the U.S.
//Department of Defense. The U.S. Government retains all rights to use,
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//Pursuant to DoD Directive 523024
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// DISTRIBUTION STATEMENT A: This software has been approved for public
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//=============================================================================

/**
 * @file PZ90Ellipsoid.hpp
 * PZ90.02 model of the Ellipsoid (as defined in table 3.2 of ICD-2008, v5.1).
 */

#ifndef GPSTK_PZ90ELLIPSOID_HPP
#define GPSTK_PZ90ELLIPSOID_HPP

#include "EllipsoidModel.hpp"

namespace gpstk
{
/** @addtogroup geodeticgroup */
//@{

class PZ90Ellipsoid : public EllipsoidModel
{
public:

    ///Defined in table 3.2 of ICD-2008 (v5.1)
    /// @return semi-major axis of Earth in meters.
    virtual double a() const throw()
    {
        return 6378136.0;
    }

    ///Defined in table 3.2 of ICD-2008 (v5.1)
    /// @return semi-major axis of Earth in km.
    virtual double a_km() const throw()
    {
        return a() / 1000.0;
    }

    /**
     * Defined in table 3.2 of the GLONASS ICD-2008 (v5.1)
     * @return inverse o flattening (ellipsoid parameter).
     */
    virtual double flatteningInverse() const throw()
    {
        return 298.25784;
    }

    /**
     * Computed from inverse flattening value as given in table 3.2
     * of the GLONASS ICD-2008 (v5.1)
     * @return flattening (ellipsoid parameter).
     */
    virtual double flattening() const throw()
    {
        return 3.35280373518e-3;
    }

    // The eccentricity and eccSquared values were computed from the
    // flattening value via the formula:
    // ecc2 = 1 - (1 - f)^2 = f*(2.0 - f)
    // ecc = sqrt(ecc2)
    /// @return eccentricity (ellipsoid parameter).
    virtual double eccentricity() const throw()
    {
        return 8.1819106432923e-2;
    }

    /// @return eccentricity squared (ellipsoid parameter).
    virtual double eccSquared() const throw()
    {
        return 6.69436617748e-3;
    }

    ///Defined in table 3.2 of ICD-2008 (v5.1)
    /// @return angular velocity of Earth in radians/sec.
    virtual double angVelocity() const throw()
    {
        return 7.292115e-5;
    }

    ///Defined in table 3.2 of ICD-2008 (v5.1)
    /// @return geocentric gravitational constant in m**3 / s**2
    virtual double gm() const throw()
    {
        return 398600.4418e9;
    }

    ///Defined in table 3.2 of ICD-2008 (v5.1)
    /// @return geocentric gravitational constant in km**3 / s**2
    virtual double gm_km() const throw()
    {
        return 398600.4418;
    }

    ///Defined in table 3.2 of ICD-2008 (v5.1)
    /// @return Speed of light in m/s.
    virtual double c() const throw()
    {
        return 299792458;
    }

    ///Defined in table 3.2 of ICD-2008 (v5.1)
    /// @return Speed of light in km/s
    virtual double c_km() const throw()
    {
        return c()/1000.0;
    }

    ///Defined in table 3.2 of ICD-2008 (v5.1)
    /// @return Returns second zonal harmonic of the geopotential.
    virtual double j20() const throw()
    {
        return (-1.08262575e-3);
    }

    /// Destructor.
    virtual ~PZ90Ellipsoid() throw() {};

}; // End of class 'PZ90Ellipsoid'

//@}

}  // End of namespace gpstk

#endif   // GPSTK_PZ90ELLIPSOID_HPP
